N2K-OS is a Graphics User Interface built for MS-DOS, FreeDOS, and DOSBox. Testing models have even shown that they will run in a Virtual Machine as well.
Initially being built on a 486 Machine that ranks as a low end Pentium 1, with 40 megabytes of ram, it currently runs like a dream for any machine of similar nature with SuperVGA and 256 Colors with ability to reach 800x600 (and soon to be much higher resolutions than that).
Slowly being developed over the last few years (each time...